Hadron Physics with Antiprotons

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Hadron Physics with Antiprotons
? Overview ? Physics with Antiprotons
_at_ PANDA (see J. Ritman, U. Wiedner)
Hadron Spectroscopy Properties of Hadrons in
Matter Double ?-Hypernuclei Options
? Conclusions
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Overview on p-induced Reactions
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Hadron Spectroscopy
Naive Quark Model Mesons (Resonances)
qq-states Baryons (Resonances) qqq-states
Particular states cc Charmonium (QCD-analog
to ee-Positronium states) LQCD Model
calculations Existence of exotic states
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Charmonium the Positronium of QCD
Charmonium
Positronium
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cc(g) - Lattice Predictions
42 K. Juge, J. Kuti, and C. Morningstar, Phys.
Rev. Lett. 90, 161601 (2003).
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Glueballs

• Self interaction between gluons
• Construction of color-neutral
• hadrons with gluons possible
• exotic glueballs dont mix with
• mesons (qq)
• 0--, 0-, 1-, 2-, 3-, ...

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PANDA Hadron Spectroscopy Program
Mass range
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PANDA Hadron Spectroscopy Program
Experiments cc
?c (11S0) experimental error on M gt 1 MeV ?
hard to understand in simple quark models ?c
(21S0) Crystal Ball result way off study of
hadronic decays hc(1P1) Spin dependence of QQ
potential Compare to triplet P-States LQCD ??
NRQCD States above the DD threshold Higher
vector states not confirmed ?(3S), ?(4S)
Expected location of 1st radial excitation of P
wave statesExpected location of narrow D wave
states, only ?(3770) seenSensitive to long range
Spin-dependent potential Nature of the new
X(3872)/ X(3940), Y(3940) and Z(3940)
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PANDA Hadron Spectroscopy Program
Example Ground State
Decay modes ??, ???
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PANDA Hadron Spectroscopy Program
Glueballs (gg)
Predictions Masses 1.5-5.0 GeV/c2 (Ground
state found? Candidates for further
states?) Quantum numbers Several spin exotics
(oddballs), e.g. JPC 2- (4.3 GeV/c2 ) Widths
100 MeV/c2 Decay into two lighter glueballs
often forbidden because of q.-n. No mixing
effects for oddballs
Decays ??, ??, ??
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PANDA Hadron Spectroscopy Program
Open Charm States
New observations

• The DS spectrum csgt c.c. was not expected to
  reveal any surprises, but ...
• Potential model
• Old measurements
• New observations
• (BaBar, CLEO-c, Belle)
• Or these are molecules?

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Merits of Antiprotons (1)
Resolution of the mass and width is only limited
by the (excellent) beam momentum resolution
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Merits of Antiprotons (2)
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High Resolution of M and G
?Crystal Ball typical resolution 10
MeV ?Fermilab 240 keV ?PANDA 20 keV
? ?p/p 10-5 needed
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Merits of Antiprotons (3)
pp-cross sections high ? Data with very high
statisties
Example pp ? ?0?0?0 (LEAR) ? f0(1500) best
candidate for Glueball ground state
Low final state multiplicities Clean spectra,
Good for PWA analyses
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Merits of Antiprotons (4)
High probability for production of exotic states
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Properties of Hadrons in Matter
Mass splittings because charge conjugation
symmetry broken at nB ? 0 Overall attraction of
Kaons due to scalar interaction KN sigma
term Mass splitting due to vector interaction
Weinberg-Tomozawa
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J/?, ? Absorption in Nuclei
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Douple ?-Hypernuclei
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Timelike Proton Form Factors at large Q2
The time like FF remains about a factor 2 above
the space like. These differences should vanish
in pQCD, thus the asymptotic behavior has not yet
been reached at these large values of q2.
(HESR up to s 25 GeV2) (PANDA probably up to
20 GeV2)
q2gt0
q2lt0
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Physics Program / Further Options
Baryon Spectroscopy New states, Quantum numbers
and decay rates
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Physics Program / Further Options
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Physics Program / Further Options
Study of reversed Deeply Virtual Compton
Scattering (DVCS) ? Nucleon
structure functions
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Conclusions
? Enormous impact in particle physics of
p-induced reactions ? p-induced reactions
have unique features Nearly all states can be
directly produced High cross sections
guarantee high statistics data ? p-beams
can be cooled very effectively ? The
planned p-experiments at FAIR will contribute to
a further understanding of the
non-perturbative sector of QCD